Session fixation

Impact

The use of Plug.Session in Pow.Plug.Session is susceptible to session fixation attacks if a persistent session store is used for Plug.Session, such as Redis or a database. Cookie store, which is used in most Phoenix apps, doesn’t have this vulnerability.

Workarounds

Call Plug.Conn.configure_session(conn, renew: true) periodically and after privilege change. A custom authorization plug can be written where the create/3 method should return the conn only after Plug.Conn.configure_session/2 have been called on it.

References

https://github.com/danschultzer/pow/commit/578ffd3d8bb8e8a26077b644222186b108da474f
https://www.owasp.org/index.php/Session_fixation